The military will continue to be deployed to key sites until the end of the bank holiday.

The UK terror threat level has been reduced from critical, back to severe, the Prime Minister announced on Saturday.

The level was increased following Monday’s Manchester Arena bombing which resulted in 22 deaths, due to fears another attack was imminent.

Operation Temperer, which allows the military to be deployed to key sites, will continue until the end of the bank holiday, Theresa May said.

PA Wire/PA ImagesThe threat level has been reduced from critical, back to severe, the Prime Minister said on Saturday, but soldiers will continue to police key sits until the end of the bank holiday weekend

Eleven people are now being held in connection with the bombing which happened at the end of a concert by Ariana Grande.

The development came as a vast security operation began to protect hundreds of Spring Bank Holiday events across Britain this weekend.

More than 1,000 armed police are on standby as major spectacles, including the FA Cup Final at Wembley and the Premiership Rugby Final at Twickenham, are expected to draw tens of thousands of people into public spaces on Saturday.

Despite the country being placed on critical alert, police have urged people to go out and enjoy themselves.

Britain’s senior counter-terror officer said “immense” progress had been made in the probe into the associates of suicide bomber Salman Abedi and a “large part” of his suspected network had been dismantled.